Technical Field
This disclosure relates to a sheet container and an image forming apparatus incorporating the sheet container.
Related Art
Various types of image forming apparatuses includes copiers, printers, facsimile machines, or multifunction peripherals (WIN) having two or more of copying, printing, scanning, facsimile transmission, plotter, and other capabilities. Such image forming apparatuses include a sheet container having a sheet tray that is removably inserted to a container body of the sheet container and accommodates sheets therein.
For example, a known sheet container includes a hook and a cancel button. The hook engages with a pin functioning as a stopper mounted on a container body of the known sheet container. The cancel button cancels the engagement of the hook with the pin. The hook includes a hook portion at the tip. An opposed end of the hook is rotatably supported by the sheet tray. When the sheet tray is inserted in the container body, the hook-shaped portion of the hook is disposed facing the pin from an upstream side in a tray removing direction of the sheet tray. According to this configuration, when the sheet tray is pulled to remove from the container body, the hook-shaped portion contacts the pin, so that the sheet tray is retained in the container body.
The cancel button is movably held by the sheet tray. When the cancel button is pressed, the hook rotates along with movement of the cancel button, and the hook-shaped portion at the tip of the hook moves from an opposing position at which the hook-shaped portion faces the pin to a retreating position to disengage the hook from the pin. Consequently, the stopper of a drawer unit (i.e., the sheet tray) to the container body is canceled, and therefore the sheet tray can be removed from the container body.
As another example, a known sheet container includes a cylinder lock that functions as a tray locking device. The cylinder lock includes a regulating member to regulate rotation of the hook. As a user inserts a key into a key hole of the cylinder lock and turns the key, the cylinder lock is rotated to move the regulating member from the retreating position to a regulating position where rotation of the hook is restrained. Accordingly, the hook-shaped portion of the hook cannot move from the opposing position to the retreating position. As a result, cancellation of retention of the sheet tray in the container body by the cancel button is prohibited.
However, in the above-described known sheet container, it is likely that the cylinder lock is locked by mistake when the sheet tray is pulled out. In this case, the sheet tray is pushed into the container body in a state that the hook-shaped portion of the hook cannot move from the opposing position to the retreating position. Then, when the hook-shaped portion that functions as a stopper target portion at the tip of the hook contacts the pin that functions as a stopper in the container body, the sheet tray cannot be inserted further into the container body. Therefore, the sheet tray cannot be attached to the image forming apparatus. Further, if the sheet tray is further pushed into the container body with the hook-shaped portion in contact with the pin, a great load is applied to the pin and the hook, and therefore can break or damage the pin and the hook.